Al-Adab Al-Mufrad #1040
Greetings
The Arabic includes the chain of narration (sanad) and the collector's commentary; the English translation shows the Prophet's words only.
حَدَّثَنَا مَطَرٌ، قَالَ: حَدَّثَنَا رَوْحُ بْنُ عُبَادَةَ، قَالَ: حَدَّثَنَا بِسْطَامٌ قَالَ: سَمِعْتُ مُعَاوِيَةَ بْنَ قُرَّةَ قَالَ: قَالَ لِي أَبِي: يَا بُنَيَّ، إِذَا مَرَّ بِكَ الرَّجُلُ فَقَالَ: السَّلاَمُ عَلَيْكُمْ، فَلاَ تَقُلْ: وَعَلَيْكَ، كَأَنَّكَ تَخُصُّهُ بِذَلِكَ وَحْدَهُ، فَإِنَّهُ لَيْسَ وَحْدَهُ، وَلَكِنْ قُلِ: السَّلامُ عَلَيْكُمْ.
Mu'awiya ibn Qurra said that his father said to him, "My son,
when a man passes by you and says, 'Peace be upon you (plural).' Do not
say, 'And on you (singular)' as if you were singling out that greeting
out for him alone. Rather say, 'Peace be upon you (plural).'"
About Al-Adab Al-Mufrad
This hadith is #1040 from Al-Adab Al-Mufrad, in the Book of Greetings.